Automatic weighing conveyer



Nov. 12, 1940. M. EvoY AUTOMATIC WEIGHING CONVEYER Filed pril 9, 1958 3Sheets-Shes?I l Nov. 12, 1940. M. EVOY AUTOMATIC WEIGHING CONVEYERFi1ed"Apri1 S, 1938 5 Sheets-Sheet 2 Lw.. w M f? /rz M Patented Nov. l2,1940 UNITED STATES PATENT OFFICE 3 Claims.

This invention is directed to a weighing conveyer, preferablyautomatically `controlled and primarily intended for use in the weighingand control of delivery of a light textile fibre such as, for example,wool.

It is an object of the present invention to provide a mechanism whichwill continuously indicate, and, if desired, record, the production orthrough-put of a textile ilbre such as wool.

10 It is a further object of this invention to produce a mechanism whichwill automatically maintain at any predetermined constant level theproduction or through-put of such textile bre.

Further objects of this invention will appear ll from the followingdescription read in conjunction with the accompanying drawings, whichillustrate a preferred embodiment of the invention, and in which:

Figure 1 is aside elevation of the mechanism in l n accordance with thepresent invention.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a diagrammatic side elevation of the weighing conveyerproper.

Il Figure 4 is a detail view of the front of the y indicating andautomatic control mechanism.

Figure 5 is a sectional view of the indicating and automatic controlmechanism.-

Figure 6 is a detail view of the .rear of the "n indicating andautomatic control mechanism', and

Figure 'I is a wiring diagram for the automatic control mechanism.

While the mechanism in accordance with this invention is obviouslysuitable for many purposes,

" it will, for clarity, be described with reference to Feeding mechanism'50 The wool is fed to the weighing conveyer by means of twosubstantially identical textile feeders A, B, which -are of conventionalconstruction and are arranged in tandem. The wool is fed by hand intothe feeder A, where a moving conveyer 55 belt Il carries it to a spikeapron I3, which in turn conveys the fibres upward past the oscillatingpicker or comb I5, through the beater I1 and eventually down the chuteI9 into feeder B. Here a similar .conveyer 2I carries the wool to aspike apron 23, which in turn conveys the wool past the 5 picker or comb25, the beater 21, and so down the chute 29 to the weighing conveyer C.Since the mechanism just described is not-novel per se and is well knownin the art, no further description thereof need be given.

The spike aprons I3 and 23 are driven at independently regulable speedsin the following manner. The beater 21 is secured to a positively drivenshaft 3I, from which is driven, by means of the chain 33 and sprocket35, one member of a suitable variable-speed transmission mechanism 31,such as, for example, a Reeves transmission. 'I'he other member of thisvariable speed transmission drives, through gears 39 and 4I, the spikeapron 23. 'Ihe variable speed transmission 31 is 20 operated by movementof the sprocket 43, which is actuated by an electric motor 45 operatingthrough a speed reducer 41.

The beater I1 of the feeder A is likewise directly connected with onemember of a secondvariable 25 speed transmission member 5I, power beingtransmitted from the driven shaft 3l by means of the chain 43. Thesecond member of the variable speed transmission 5I drives, throughgears 53 and 55, the spike apron I3. 'I'he variable speed 30transmission is controlled by movement of the hand wheel 51.

The weighing conveyer The weighing conveyer C comprises essentially 35an endless conveyer belt 1I which receives the wool bres from the chute23 of the feeder B and delivers them at 13 to a second conveyer, notshown, which takes them to any desired processing point. The conveyerbelt 1I is of such size 40 and is driven at constant, fixed rate ofspeed such, for example, that it will have upon it at all times oneminutes production of wool fibres.

The conveyer belt 1I is supported on and driven by a pair of end rolls15 and a central supporting 45 roll 11. 'I'hese rolls are driven, asbest shown in' Figure 3, by chains 19 and 8i, from an electric motor 83and speed reducer 85. The rolls 15 are journaled in a pair oflongitudinal frame members 81, while the roll 11 is journaled in a pairof 50 brackets 83 secured to the frame lmembers 81, and

the motor 83 and speed changer 85 are mounted on a platform 3| likewisesuspended from one of the frame members 81. Accordingly, the entireweight of the weighing conveyer and associated 55 driving elements issupported on the two frame members 81. The'frame members 81 in turn restupon a pair of cross bars 93 secured to the lower ends of four hangers95. Each hanger 95 is pivotally connected at its upper end to the shortarm of a lever 91. These levers 91 form two opposed pairs, the levers ofeach pair being keyed, intermediate their ends, to a floating shaft 99.At their ends opposite the point of connection with the hangers 95, thelevers are pivotally connected to fixed hangers |0| which are xedlysecured in the ceiling. Keyed to each of the two shafts 99 intermediateits ends is an arm |03, and these two arms are pivotally connected tothe upper end of a single rod |05.

The lower end of the rod |05 is pivotally secured adjacent the free endof the lever |01 (which is also provided with a counter weight |09),which lever has a fixed pivot at and, intermediate the fixed pivot andthe point of connection-of the link |05, is connected with the rod ||3.This rod |'|3, which is provided with a turnbuckle ||5, is connected inconventional manner with the scale ||1, so that its movement istransmitted to the pointer ||9.

The system of levers just described is all enclosed within a housing|2|, while the scale ||1 is enclosed in a second housing |23 supportedjust below the housing |2|.

By the mechanism just described variations in load carried on theconveyer belt 1| will be transmitted, in the ratio determined by thelever mechanism, to the scale |1, and indicated thereon by means of thepointer ||9. The scale dial |25 will, conveniently, be graduated inunits sixty times as great as that which the scale is really weighing.Thus, for example, the scale dial will indicate pounds per hour passingover the conveyer belt 1| instead of pounds per minute.

Associated with the scale ||1 in conventional manner there may be arecording mechanism |21 calibrated to read in pounds per hour passingover the conveyer belt 1| at any given moment of time. In this way apermanent record of production and of the accuracy of control thereofmay be kept.

The automatic control mechanism The automatic control mechanism isassociated with the indicating dial V|25 of scale ||1, as shown best inFigures 4, 5 and 6. 'I'he indicating dial |25 of the scale ||1 is xed,while the pointer ||9 rotates with variations in load on the conveyerbelt 1| (in Figures 4, 5 and 6, for convenience, the connections betweenthe pointer ||9 and the weighing mechanism of the scale have not beenshown). A ring |4| is independently rotatable around the periphery ofthe xed indicating dial |25, and carries a pointer |43, which may be setat any desired reading on the dial |25. The ring |4| is provided withgear teeth on its-inner surface., which mesh with a pinion |45 set on ashaft |41 and operated by means of a small crank |49. A similar ring |5|is mounted behind the fixed dial |25, and is likewise moved by a pinion|53 mounted on the same shaft as the pinion |45. The ring |5| carries abracket |55 supporting a photoelectric cell |51 and a bracket |59supporting a source of light I6|, the source of light and thephotoelectric cell being arranged in line one with the other as shown inFigure 5.

By movement of the crank |49 the two rings |4|, |5| are accordinglycaused to move to the same extent, and consequently the position, withreference to the circumference of the i'lxed dial |25, of thephotoelectric cell |51 is fixed in relation to the position of thepointer |43 carried by the ring |4|.

Secured to the same spindle |63 on which the pointer I9 is mounted, butpositioned at the rear of the dial |25, is a disc |65, cut on twodiameters, so that half the periphery lies on a radius appreciablygreater than that of the other half. The gradation from one radius tothe other, along the lines |61, is relatively gradual and makes an angleof about 30 with a tangent. The disc |65 is positioned to rotate betweenthe photoelectric cell |51 and the source of light |6|, so that when itsportion of greater radius |69 is positioned between the source of lightand the photoelectric cell, no illumination will fall on the cell; whilewhen its portion of lesser radius |1| is in the corresponding position,the cell will receive full illumination. When the disc rotates so thatthe portions |61 are positioned between the cell and the source oflight, the cell will receive a varying quantity of light, depending uponthe exact position of the disc.

Accordingly, since the disc |65 rotates with the pointer ||9, the amountof light falling on the photoelectric cell will be determined by theload carried at any moment on the conveyer belt 1|.

The photoelectric cell |51 is connected to a sensitive relay |8|, oneside of which is connected to the low voltage side of a power relay |83,and the other side of which is connected to the low voltage side of asecond power relay |85, both connections being made through a timeswitch |81. Closing of the power relay |83 will-cause motor 45associated with the textile feeder' t0 be energized to rotate in onedirection, while closing of the power relay |85 will cause motor 45 tobe energized to rotate in the opposite direction, as shown in Figure 7.

The time switch |81 comprises two cams |89 and |9|, respectively,rotated together at a constant slow speed, for example, of about 2 R. P.M. The two cams may be relatively adjusted and clamped in adjustedposition by means of the screw |93. A contact member |95 rides on thecam |89, while a second contact member |91 rides on the cam |9|. Sincecontact can only be made when member |91 is riding on the high part ofcam |9| and member |95 is riding on the low part of cam |69, thesensitive relay |8| will only be energized when the contact members areriding between the points a and on the two cams, that is, as shown inFigure 7, for about one quarter of the revolution.

Operation of device We shall assume it is desired to obtain a throughputof wool libres of 550 pounds per hour. The pointer |43 carried by thering |4| will be set at this value, as shown in Figure 4, by movement ofthe crank |49. This will rotate the ring |5| so as to bring thephotoelectric cell |51 and its associated light source to a point on theperlphery of the dial |25 such that, when the pointer ||9 stands at avalue higher than 550, the disc |65 will be so positioned that theamount of illumination falling on the photoelectric cell |51 will bebelow the critical value necessary to energize the sensitive relay |0|,while when the pointer ||9 stands below` the value of 550 pounds, theamount of mummation win be in ex- .cess of such critical value.-

The operator will then feed fibres to the feeder A at approximately thedesired rate, very considerable variations in the rate of feed to feederA being permissible. At the same time the speed of the spike apron I8will be so adjusted by movement of the hand wheel 51 that the hopper ofthe second feeder B will be kept lled to a substantial'ly constantlevel.' This levelneed 'by no means be kept exactly constant, but thefeeder B must neither be starved so that it is unable to deliver theproper quantity to the weighing conveyer C, nor must it be overiedk sothat bres will spill out. In practice, the hopper-of the second feeder Bwill be found to be filling or emptying slowly all the time, and atleast hourly adjustments of the hand wheel 51 will be necessary ordesirable. This could be done automatically, the control beingaccomplished by a beam of light directed across the hopper of the secondfeeder B and onto a photoelectric cell; but such automatic control ofthe rst feeder A is not ordinarily necessary.

The second feeder B will deliver the wool bres down the chute 29 ontothe conveyer belt 1| forming a layer rising to approximately the heightshown by the broken line in Figure 1. The conveyer belt 1 I, asindicated, will have upon it at all times one minutes production; andconsequently, if the production is to be 550 pounds per hour, it willcarry slightly more than 9 pounds of fibres.

Through the weighing mechanism described the weight of the fibres on theconveyer belt 1| at any moment is transmitted to the scale ||1 where itis vshown by the pointer ||9 in pounds per hour. At the same time apermanent record is being made by the recording mechanism |21.

If slightly more than the desired quantity of wool fibres are presentAon the conveyer belt 1|, the pointer ||8 will, of course, indicate ahigher rate of production than the desired 550 pounds per hour. Whenthis occurs, as previously described, the disc occupies such a positionwith respect to the photoelectrlc cell |51 that the amount ofillumination falling on the latter is below that necessary to causeenergization of the sensitive relay |8|. Consequently, the spring |82will hold the contact arm of this relay in position to causeenergization of the power relay |88. In such case, when the time switch|89 functions so as to close the contacts |95, '|91, the powerrelay |88will be energized for a brief interval, and the motor 85 will be drivento cause rotation of the pinion I8, which in turn operates the speedchanging mechanism 81 so as to decrease the rate at which the spikeapron 28 travels and thus decrease the quantity of fibres fed to theconveyer belt 1|. i

On the other hand, if the weight of fibres on t belt 1| is less than thedesired quantity, the pointer ||9 will indicate a throughput less thanthe desired 550 pounds per hour; and the position of the ydisc |55 willbe such that the illumination falling on the photoelectric cell |51 issufficient to energize the sensitive relay |8| and cause the contactarm-thereof to close, against the action 'of the spring |82, the circuitto the power relay |85. In this way, when the time lclock |81 causes thecontacts |95, |91 'to close,

through the speed changer 31, speeding up the spike apron 23.

In practice, with the time switch |81 operating at frequent regularintervals, the speed of the conveyor 23 will be accurately controlled todeliver a substantially constant predetermined quantity of wool iibrestothe conveyer belt 1| and thence to the processing equipment. In anactual installation of the character described, the weight of fibrespassing over the conveyer per hour will become substantially constantwithin twenty minutes of operation and will continue constant, with atotal variation of not more than 0.25%, throughout the day.

What I claim and desire to protect by Letters Patent is:

1.l An apparatus of the character described comprising, in combination,aconveyer belt and a Weighing means associated therewith, means forfeeding material to the conveyer belt, including two independentlycontrollable feeders arranged in tandem, so that one feeds the other,and means actuable by said weighing means for controllingthe rate ofoperation of that feeder nearer in sequence to the conveyer belt wherebymaterial may be fed to and over said conveyer at a predetermined rate, asource of light, a photoelectric cell, a rotatable member ,mountedbetween the photoelectric cell and the source of light and movableresponsively to the load on said weighing means, said member havingopposite obliquely bounded portions whereby the amount of light fallingupon the photoelectric cell depends upon the load carried at any mo-`ment on the weighing c'onveyer belt, and the obliquely bounded portionsprovide relatively gradual varying interception of light to be receivedon the cell depending upon the position assumed by therotatable memberthereby maintaining an even feed of the material.

2. An apparatus as setv forth, comprisingy a conveyer belt, Weighingmeans associated therewith, means for feeding material to the conveyerbelt, means actuable by said weighing means for controlling, the rate ofoperation of the feeding means, whereby material may be fed to and oversaid conveyer belt at a predetermined substantially constant speed, saidcontrolling means including a rotatable member movable responsively tothe load on said weighing means, a source of light, alphoto-electriccell, said rotatable member being mounted between said photo-electriccell and the source of light, wherby the amount of light falling uponphoto-electric cell depends upon the load carried at any moment on theweighing conveyer belt, said rotatable member having opposite obliquelybounded portions, said obliquely bounded portions acting for relativelygradual varying the interception of the light to be received on saidcell depending upon the position assumed by said rotatable member,thereby maintaining an even feedof the material.

3. The combination with a conveyer belt, adapted Ito contain upon itl atall times one minutes production of wool fibres, of weighing means.associated therewith, means for feeding said material to the conveyerbelt and comprising independently controllable feeders in tandem wherebyone feeds the other, means actuated by said `weighing means forcontrolling the rate of operation of that feeder nearest in sequence tosaid conveyer belt, whereby said material can be fed to and over saidconveyer belt at a substantially constant predetermined rate of speed,said means including a rotatable disk-like member formed with portionshaving diirerent radii and opposite intervening obliquely boundedportions, said member being connected to the weighing means for movementproportionate to the load thereon, a photoelectrc cell and a source otlight at opposite sides of said member, whereby the amount of lightfalling upon said photoelectric cell will depend on the load carried atany moment on the conveyer belt, and the obliquely bounded oppositeportions ot the member will cause a relatively gradually varyingquantity of light to be received on'the cell depending upon the exactposition of said member and connections from the cell to the feedernearest in sequence to the conveyer belt to control the rate of i'eed inaccordance with cell illumination, whereby the rate of feed ismaintained substantially constant.

MARTIN EVOY.

